The present invention relates to a form tool head and more particularly to a form tool head having an improved adjusting mechanism for varying the depth of the punching or stamping done by the punch press.
Form tools are used in single station or turret press machines. Form tools must be set up to the machine's punching stroke and the thickness of the material on which the punching or forming operation is to be performed. The set up of a form tool in a press is critical. Almost all problems with forming tools occur during set up Incorrectly setting the height of a form tool during set up can damage the tool and possibly the press. If the height of the form tool moves during a punching operation (after initial set up), for example, damage to the form tool and scrapped parts will likely be the result.
The setting of the tool length can be a tedious and time consuming process beginning with the loosening of set screws which conventionally have been used for locking an internally threaded tool head to a threaded shaft of a punch tool. Next the form tool head must be turned in a clockwise or counter-clockwise direction to move the tool head along the threaded shaft of the form tool to increase or decrease the tool length as required. Then the loosened set screws must be tightened to lock the form tool head in place against the shaft of the form tool. The loosening and tightening of the set screws may have to be repeated several times to achieve the precise adjustment of the form tool length required.
The tool head used in modern high speed presses is subjected to large repetitious forces during the operation of the machine. The set screws may tend to work loose and the threads of the threaded shaft or head may become damaged or even stripped causing the tool's height or length to change midway through the production cycle. The value of the lost production, scrap material produced and damage to the press would be shockingly high. The inherent disadvantages that result from the use of set screws for locking the form tool head in adjusted position are also common to other locking devices such as clips or keys which can work loose.
It is an object of the present invention to provide a form tool head incorporating a mechanism for quickly and accurately making length adjustments of the form tool head.
It is a further object to provide an adjustment mechanism that achieves a positive lock of the length of the tool so that the height of the tool cannot change midway through a production run.
It is yet a further object of the present invention to substantially reduce the effort and time required to adjust a form tool's length to a press machine's punching stroke and the thickness of the material.
It is yet a further object of the present invention to provide a form tool head having an adjustment mechanism that permits the length of the tool to be quickly adjusted in small movement increments until the length is brought to an accurate working tolerance.
It is yet a further object to achieve a positive lock of the form tool head length without the use of set screws, clips or keys.
It is yet a further object to provide an adjustment mechanism that permits the form tool head length adjustments to be done easily while the tool remains in the press. With larger station tools weighing from 14 to 28 pounds, the ability to make adjustments with the form tool head in the press results in a substantial saving in machine down time.